


Dream Come True

by FairyNiamh



Category: Supernatural
Genre: Alpha Castiel (Supernatural), Alpha John Winchester, Alpha/Beta/Omega Dynamics, Bottom Dean Winchester, Consensual Underage Sex, Dead Dove: Do Not Eat, Implied Mpreg, Incest, M/M, Male Lactation, Mating, Omega Dean, Oral Sex, Threesome - M/M/M, boy pussy
Language: English
Status: Completed
Published: 2020-07-22
Updated: 2020-07-22
Packaged: 2021-03-05 04:33:33
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,185
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25438486
Author URL: https://archiveofourown.org/users/FairyNiamh/pseuds/FairyNiamh
Summary: Cas' dream finally comes true.
Relationships: Castiel/Dean Winchester/John Winchester
Kudos: 155





	Dream Come True

**Author's Note:**

> Written on a Kindle Fire.
> 
> In this world, all omegas have both male and female genitalia and stop growing (not aging) when they are given Alpha sperm. Yes, Cas' morals a extremely effed up.

Dream Come True

Castiel had agreed to watch his older brother's oldest boy while he took his youngest son to soccer practice. Something Dean had no interest in. In fact, he didn't like to _play_ any sports.

He preferred to stay at home to cook (only under supervision), clean, and lately he had taken to using clothes that were worn out or grown out of to make baby quilts for the pregnant Omegas at his school.

Cas had asked his brother; if he thought that the boy was destined to be an Omega. John had grown angry at hearing that and declared that both his boys would be strapping Alphas, like him. 

He hated to disagree with his brother, but he had his suspicions about his beautiful nephew. Which was the reason he had gotten the boy used to gentle touches and kisses. Nothing passionate or outright sexual. Pecks on the lips and running his hand on the boy's whole body... Okay, slightly sexual.

Still, today was different. Surely, his brother could smell the onset of the boy's first heat on his soon to be Omega son. Was Castiel expected to ignore that delicious smell? Besides, John _knew_ that the boy was at the _perfect_ size for an Omega mate, in Cas' opinion.

The most wonderful thing about Omegas is that they full on stop growing once they take their first knot. Growing, not maturing. He loved to watch films starring Littles being themselves. Especially the porn. 

"Uncle Cas!" the Little, excuse him, the boy greeted him.

He caught the human sized rocket that had been launched at him with a smile and a hug. "Look at you. Have you grown since I last saw you?"

Dean wrinkled his nose and pouted, "Only a little bit. Dad is mad at me because Sammy is growing faster than I am."

"I'm not mad. I know you'll be as tall as me, where your little brother will be as tall as a house. Finish your homework and study that book I bought for you," John directed his son and tousled his hair.

"Yes dad," the boy answered sullenly.

"I should be back before 10 tonight or so. I told Sam he could stay the weekend with his friend, but I have to drop him off. The fridge is full, but if you want takeout there's money in the normal place. Dean, behave and do what your Uncle tells you to do." John rambled out loud and without a hug or kiss to his eldest son, the pair was gone.

"Hey Dean," he said softly, following the boy to sit on the couch behind him.

He didn't answer, he just sat on the floor by the coffee table, and began to read a mechanic's manual, while silently crying.

There was a lot he could ignore, but not the sad boy in front of him. "No more book for you, I don't give a fuck what your dad thinks. Did you know that there are a bunch of boys that are similar to you?"

"You're lying," came the hopeful sounding rebuttal.

"I'll prove it," he countered, pulling out his laptop and loading his favorite Little porn. He deliberately did not make the video full screen as he placed the boy between his legs on the couch.

He hit play and let his hand travel under the boy's shirt to play with the small developing breasts he had recently sprouted. Dean leaned into the fondling, unknowingly silently asking for more.

The boy gasped and squirmed when the Little was finally being fucked. "Why are they doing that?"

"Exactly what you think they are doing," he muttered and kissed the boy's neck.

"He's like, what eight years old or younger. That's too young! This is kiddie porn and illegal," he declared firmly. 

Cas had to chuckle at the indignation in the boy's voice. "He's a Little and an Omega, like you. He's also eighteen."

"No way, he's 9 at most and I'm not an Omega. Dad said I am probably a Beta, " he defended his thoughts.

He nuzzled his nephew's ear as he whispered, "Tell me what you think you know about Omegas."

Dean squirmed as he quickly answered, "They're weak. They like to cook and clean, their butt gets wet when they get horny, they want to be..."

"What do they want to be?" he pushed for the right answer.

"Pregnant," he sighed wistfully as he placed his hand on his flat stomach

Watching his nephew deny himself was upsetting. "Do you know how old most of the Omegas are, when they carry their first child for the state?"

"Fifteen?" Came the unsure response. 

"Eleven. You're thirteen Dean. You should have already had one child with another on the way for your Alpha," he stressed

The boy's lips quivered at the thought. "I don't have an Alpha. What if I'm too old and no one will have me?"

Cas turned the boy's head and claimed his mouth in a passionate kiss. Just as they got a little hot and heavy the boy pulled away apologizing. "What on earth are you going on about?"

"If I am an Omega, that means I tempted you to kiss me. I'm sorry. I know incest is against nature and wrong. I didn't mean to," he rambled.

He sighed in relief. "Sweetheart, I think it's time you knew the family secret."

"Wait, there's a family secret?" he squeaked out in shock.

The Alpha hugged him tighter. "Yup, twenty-five years ago your grandfather purchased and adopted a young blond boy, in hopes that he would be present as an Omega to be the perfect mate for your dad. Instead, I presented as an Alpha and your father fell in love with your mother."

"So, you're not my Uncle?" he asked sadly.

Cas kissed the boy again and slipped his hand down the back of his shorts to play with his wet hole. "I'm your Uncle, but we are not blood related. Dean Winchester, would you do me the honor of being my mate, my perfect Omega mate?"

"Dad is going to be so mad at us, but yes. I've been dreaming of you fucking me and knocking me up with our child for years, " he joyfully accepted. He sighed as he felt the weight of his secret crush lifted off his shoulders.

The older man picked up the young man and traversed the modest house to the spare bedroom where they had put him in for his visit. He had been working on the boy for the last six years. Slipping tiny amounts of his come into the kid's drink and food since he was seven, effectively slowing his growth and ensuring his designation. This tiny body was everything Cas ever wanted in his mate. He could hardly wait until the boy was round with his child and had huge milk heavy tits for him to nurse on.

Once inside the room he swiftly removed his clothes and then turned his attention to his soon to be mate. He removed the too big clothes and began to suckle on his mate's tiny breast buds as his hands roamed the boy's perfect body.

Two of his fingers easily slipped inside his nephew's wet ass. He took it as a sign that this was meant to happen. Despite John's wishes, Dean was an Omega, and as soon as he gave the boy his knot and bite, he would be his, forever. 

He knew he should stretch the boy more, but six years was enough training and waiting. He rolled his nephew to his side and pulled him down until the tip of his painful erection brushed against the wonderfully tight virgin ring. "Deep breaths and relax. This may hurt a bit at first."

He probably should have eaten him out, but as he held the boy's leg over his shoulder and slowly pushed inside, it took everything in him to go slow and not just take what had been offered.

Amazingly, Dean neither tensed up nor cried out in pain. The boy reached down to feel where they were connected and moaned like a good Omega. "It feels so good, Uncle Cas. Your cock is huge and it feels okay."

"Only okay?" he asked, trying not to laugh.

The teen whined and swirled his hips, "It's not enough."

Rather than argue, Cas slammed all the way in his mate's tight ass, causing them both to moan. He looked down and was surprised to see the outline of his dick. "Dean, look." He directed, as he ran his hand over the outline of his cock moaning when he felt Dean's small hand join his.

"More, please!" the tiny teen begged as he gripped his Uncle's invading cock, through the bulge in his belly.

He couldn't resist any longer. He had really trained his nephew to be the perfect Omega Bride for himself. He liked to cook, clean, and fuck like it was what he was born to do. "I'm going to knot your bitch ass and put my children inside of you. Then, I'll bite you just there, to lay claim of you, forever," he panted and touched his nephew's neck.

"Yes, I want that. Mate me. Fuck me harder and make me carry your babies. Come on, Uncle Cas, make me your Omega bitch," Dean begged and tightened his hand around his cock. He had to wonder if his boy was leaving bruises on his stomach. That was something to wonder about later.

The foul language coming out of something that looked so innocent made some deep dark part of him snap. Not that his darkness was that well-hidden.

He fucked Dean harder than he had intended, but his baby bitch was begging for it. The one thing he did that the Omega didn't enjoy and caused him to scream in pain, was when he pinched the boy's nipples hard and twisted.

Suddenly, he pulled out, dropped his nephew's leg, flipped him to his hands and knees, and resumed fucking the moaning mess under him. "I'm fixing to knot your ass, baby. Gonna put a baby in your tummy. Maybe we'll wind up with twins. Do you want it? Do you think you can handle a knot in your tight little ass?"

"Please, Alpha, I need it," he begged, pushing back to meet the powerful thrusts.

Rather than say anything, he chased after what _he_ wanted and needed to seal the deal before John got back home. He knew several things that would make this perfect... but first, "Here it comes. Going to knot your ass, now."

Dean screamed and came hard when he felt the knot tie them together and once Uncle Cas gave him the claiming bite, he knew nothing, but bliss and joy as the bond settled in.

Cas sat up and allowed his mate to continue to ride his knot. The claiming bite had thrown the boy into his first full blown heat. He would be insatiable until there was a child in his womb, which would take a few days to weeks to grow enough for the body to acknowledge.

He had a shit eating grin on face when John got home and found Dean being fed fruit while begging Uncle Cas to put a baby in him. "Don't worry, brother. I have been waiting for you, since Dean went into heat and I woke up to him riding my cock demanding a baby. I felt bad that you would have to try to find a mate for him. So, I gave him my bite. I guess it's a good thing that I just signed off on a large house."

John was confused and moaned as he watched his brother turn around and spread their legs, showing off where the pair were connected and how Dean was doing the grinding back in the Alpha's knot.

"Will I be allowed to see my son once this is all finished?" he asked softly.

This caused Cas to laugh and hug his mate tight. "Of course, you can. Dean loves you and I know he'll want the grandfather of our children to be in our lives."

"Jesus, I'm too young to be a grandfather. Our parents are rolling in their graves," he moaned as he walked up to touch his son's come swollen stomach.

"They're throwing a party. They always wanted us to be together. Mom cried so hard when you married Mary and dad beat up his Chevy truck when I popped my knot. Dean truly is our last chance to have a happy family together," he explained.

The man looked lost, but Cas could see a glimmer of something else in his eyes. He pulled John forward and kissed him deeply as he removed his brother's jacket. He grinned when he saw small hands tackle the buttons on his dad's shirt

"I have been in love with you, since Dad first brought me home. Dad might of been mad, but I cried my heart out when I popped my knot. Then your beautiful son was born. I knew he was destined to be an Omega. I lavished him with love and helped him when he showed an interest in cooking, organizing, and cleaning. Now, he is interested in children. As a pair of Alphas, we cannot be together, that's the law; but if we are both seduced by the same Omega… well, then we are outstanding Alphas. After all, we put our egos and hormones aside, to provide the best possible experience and environment for our Omega," he explained not pausing in divesting the older man of his clothes.

"I thought I was going to be a grandfather," he asked blandly, as his pants were dropped and he was pushed on the couch.

"Why can't you be both?" It was Dean who asked from his knotted perch.

"If you don't want this, do not want us, you need to speak up, now. My knot is slipping free and Dean has voiced his frustration and disappointment, that you're not going to want him as your mate or son, because he's an Omega. I want to share the joy that is your son's heart and body with you," Castiel declared.

Without thinking or talking, John pulled his son down to kiss deeply. He moaned when Cas helped the boy find and take his cock in his tight ass. He knew this was morally wrong, but it felt like heaven. He had not been able to bed anyone after Mary had died. Maybe, this was what he had been waiting for all this time.

Cas was far from idle during this time. He kissed John, suckled on Dean's tiny tits, or played with the boy's tiny cocklet. Well, he only did the last two, until the older Alpha used his son like a fleshlight.

"Are you going to claim our Omega? He is so needy that he hopped right on your cock without asking for permission first. He's sweet and needy, but I need another strong Alpha to help me satisfy him sexually and emotionally. Won't you help us, John?" he asked as he nibbled his brother's neck.

"Please, Daddy. I need you and Uncle Cas to mate and breed me full of babies. I want to feel your knot. Please, " Dean begged and exposed the already marked side of his neck.

There were no sweet words of warning. John simply pulled his son down on his knot and placed his mating bite mark beside Cas' mark. He closed his eyes and moaned as he felt the bond between the three of them snap in place and solidify. He gingerly lapped at the blood trickling from the bite. "So, how long have you two miscreants been planning on seducing me?"

Cas smiled and answered honestly, "About an hour. My original plan was to rub Dean's new status in your face, before moving to the house I had built in the woods of Alabama. Then I saw the lust in your eyes and the 'why not me too' look. The house is big enough for all of us. The nearest neighbor is 15 miles to the north. My only concern is Sammy."

Dean hummed and rocked back on his Daddy's cock. "We should move, before you tell him. This is natural and my mates are the best-looking Alphas I have ever seen."

Cas smiled and ran his fingers through his mates’ sweaty mane. "We can also tell him the family secret. It should make him a little more sure of my mating. He loves to read. So, I can accidentally leave out my 'How to care for Omegas' guide. Which does encourage them to have more than one Alpha, but no more than three."

Dean growled at his mate. "No, to bring Sam into the fold. I don't want another Alpha. The two I have are perfect for me. I may be a slut for yours and Dad's knots, but if another Alpha tries, they will soon be liberated of their knot. You know I can do it. Dad taught me how to dress a fresh kill and I have gelded a few bulls when dad was a farmhand."

"Noted! John, how did we get such a feisty, yet obedient Omega?" he chuckled as he ran his hands over their mate's small body.

"Because, I raised him right. No one walks out or on a Winchester. Not even Omega Winchesters, " John hugged his mate tight before rubbing his come bloated belly. The boy already looked like he was sporting a small baby bump and looked even more beautiful than norm. 

Neither of the men expected the Omega to lunge forward and bite his dad's mating gland, then he pulled Castiel in and bit him as well. “Turn around is fair play. You two should bite over where I bit. Since your lust and hearts are with each other.”

“An Alpha _cannot_ claim another Alpha,” Cas explained calmly. 

“Duh, it's symbolic and strictly between the three of us. That's why I said to put it over _MY_ mark,” he explained with a roll of his eyes.

Slowly, the two Alphas did as Dean suggested. He grabbed their cocks as pumped them swiftly as the pair made out. He encouraged them to move together and wrapped his mouth around the men's cock heads and sucked as much as he could as the Alphas enjoyed one another and their Omega's mouth.

Dean worked the two forming knots and braced himself for what was to come. Both the men held his head in place and moaned in one another's mouth as the boy swallowed as much as he could. Before they all fell to the bed, breathing heavily and basked in their euphoria. 

It was clear that life would never be boring for the unlikely trio and they were all happy with that. They could work out the finer details later. After Dean was out of heat and knocked up. They could not wait to see their boy round with child.

-fin-


End file.
